Jigging is one of the oldest methods for concentrating ores and is still widely used. It is a gravimetric method of concentration which utilizes differences in the densities of wanted and unwanted materials to effect their separation. In jigging, water is strongly pulsed upward and downward through a suspended bed of particles. After sufficient pulsation, the top portion of the bed becomes an accumulation of the lighter gangue, which can be rejected, while the lower portion contains the heavier enriched concentrate.
Typical jigs use a jig tank which is open at its top and bottom ends. The top of the jig tank includes a perforated, tapered, and inclined chute through which the material being separated flows to the tank. Oversized material is prevented from entering the jig tank by the perforated screens, and caused to flow down the tapered portion of the chute to be discharged from the jig. Water pulsations within the jig also cause the gangue to collect in the upper portions of the jig tank and flow from the jig out the discharge end of the chute. The lower portion of the jig tank is angled inwardly and joins with a vertically movable cone by means of a fluid-tight flexible diaphragm. The movable cone is typically mounted to a pivotal frame arm, commonly referred to as a walking beam, which is pivotally driven to generate the pulsations within the tank.
This invention relates to a simpler and more reliable mechanical drive for imparting pivotal motion to the pivotal frame arm or walking beam.